Adsense: User Search History Used To Determine Ads Displayed?

I'm guessing this is nothing new, but it's the first time that I have noticed it...

I was searching Google this morning, trying to find a resort I stayed at many years ago. Pretty much immediatly after this I realised that I should probably do some work so I started by checking Ezine Articles to see if one I uploaded recently had been accepted yet.

But what I found interesting was the Adsense adverts on the article page - most of these were related to the subject of the article/page (rattan/cane furniture), but in the results at the top of the page there were a few surprises:

[attachment=969:screengrab.gif]

As you can see from the above, all the ads with the full title, description and URL are relevant to the article/page, but the keyword only ads at the top of the page are a mixed bag - 'Rattan Furniture' makes sense to the page, but the otehrs seem related to my earlier searches rather than the page content.

Just to be clear, I had been searching for various Maldives based terms including 'Male' (the capital of the Maldives) rather than male breast surgery as the ads in the screen shot may suggest!

I was not signed into any Google account so presume that google had used cookies to record my recent searches and was serving ads based on this info.

Anyhow, just an observation that I thought I'd mention as I had not noticed it happen before. I don't use Adsense on any of my sites at the moment but when I did I felt it was important that I could to a degree control the ads displayed through the content of my site. Not sure how I would feel about ad's for totally unrelated subject appearing, albeit to people who have searched for them previously?

You can switch this off. Somewhere in your Google account settings, there is an option to disable the use of your search history in this way. (Sorry I can't remember exactly where to do this, but I know it can be done.)

When I say "you" can switch if off, I mean the web user - the one who's performing the searches and viewing the ads. For most such people, the feature is a positive, in that it gives you ads that are more likely to be of interest.

But for AdSense publishers, it makes sense to disable it. If you don't, you can't get an accurate idea of the ads that are being delivered to your visitors.